This invention relates to a printing system, which is composed of a computer and a printing apparatus connected via a communication line, a printing apparatus and a printing control method.
A problem that can occur in a color printing apparatus is misregistration of color planes in an output image caused by the mechanisms for the printing and paper transport functions. In the prior art, this is dealt with by correcting the print data in the printer controller using a dither matrix that dots grow in longitudinal direction (hereinafter longitudinal-growth dither matrix).
Further, when data is binarized and transmitted to a printing apparatus by a client computer that processes the data, the computer corrects the print data using a longitudinal-growth dither matrix as the dither matrix used in binarization.
However, since the dither matrix used at the time of binarization processing in the printing apparatus or client computer in the above-described prior art is a unique longitudinal-growth dither matrix that corresponds to the printing orientation (portrait or landscape) and the direction in which the paper is transported, appropriate measures for dealing with misregistration cannot be implemented in regard to the orientation of the print data and the paper transport direction.